JP2012169261A - Flexible flat cable using ring conductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible flat cable using ring conductors.SOLUTION: A flexible flat cable using ring conductors comprises: ring conductors; and upper and lower base films 100 and 200 covering upper and lower parts of the ring conductors. In the flexible flat cable, a rectangular conductor 10 formed by rolling a part of each of the ring conductors before the upper and lower base films are covered is exposed in a terminal part of the flexible flat cable, the rectangular conductors exposed in the terminal part are supported by the lower base film in a form of being attached to the lower base film when the ring conductors and the rectangular conductors are attached to the lower base film, and the lower base film is integrally formed over an entire length of the flexible flat cable including the terminal part.

Description

  The present invention relates to a flexible flat cable using an annular conductor. More specifically, the present invention manufactures a flat cable using an annular conductor, and the terminal portion of the flexible flat cable exhibits the shape of a rectangular conductor. It is for manufacturing such a flexible flat cable continuously.

  Usually, a flexible flat cable is used for an application in which a signal is transmitted between electronic components by being inserted into a connector. This type of flexible flat cable is manufactured by attaching a base film or the like on and under a linear conductor for transmitting a signal. The linear conductor is an annular conductor having a circular cross section or a flat conductor having a rectangular cross section. The annular conductor is inserted into and connected to a pressing blade provided in the contact of the connector or an engagement groove of the printed circuit board, and the flat conductor is mainly used in a form of being pressed and contacted with the terminal portion of the connector. .

  In order to allow the user to select and use such an annular conductor or a rectangular conductor arbitrarily, a flexible flat in which a part of the annular conductor is rolled to form a rectangular conductor and then a base film is pasted up and down. A cable has been proposed (see, for example, Patent Document 1 below). According to this document, if necessary, the annular conductor or the flat conductor can be connected to the connector or the printed circuit board by cutting out the region where the annular conductor or the flat conductor is located and notching the upper and lower base films. The technical idea to do is disclosed. When the flat conductor is exposed and used, the end of the flexible flat cable is processed in a form in which a lower reinforcing plate is separately attached to the flat conductor, and then the flexible flat cable is inserted into the connector.

  Furthermore, the base film at the end of the flexible flat cable is notched to expose the annular conductor, and then the exposed annular conductor is rolled into a rectangular conductor, and a separate reinforcing plate is attached to the lower end of the rectangular conductor. It has been proposed to fix the position of a rectangular conductor by using it (see, for example, Patent Documents 2 and 3 below).

  In the prior art, after forming the end by cutting a predetermined length of the flexible flat cable, a pre-processed rectangular conductor is exposed at the end (Patent Document 1), or at the end The annular conductor is exposed and then rolled to be processed as a flat conductor (Patent Documents 2 and 3). In these cases, the flexible flat cable must be cut to a predetermined length, and the base film layer at the end thereof must be cut out one by one. Therefore, productivity has to be very low. In addition, since a laser or the like is used to cut out the base film without damaging the linear conductor, the cut surface of the synthetic resin base film is not finished cleanly, and the remaining base film is also roughened by heat. There is an inconvenience that deformation occurs.

  In addition, the recent narrowing of the pitch of various connector terminals is remarkable, and is currently becoming narrower to about 0.4 to 0.5 mm. For this reason, the flat conductor exposed at the end of the flexible flat cable used here is also required to have a very narrow width, and it is necessary to arrange it with extremely high accuracy in accordance with the pitch of the terminals. However, when the reinforcing plate is attached after the flat conductor is exposed as in the prior art, there is an inconvenience that it is very difficult to arrange and fix the flat conductor with high accuracy.

Japanese Unexamined Patent Publication No. 2002-56721 (February 22, 2002, page 2, paragraphs [0005]-[0006]), page 3, paragraphs [0021], all drawings JP 2010-49971 (March 4, 2010, page 3, paragraph [0012], page 5, paragraph [0033]) Japanese Unexamined Patent Application Publication No. 2010-192287 (September 2, 2010, page 5, paragraph [0015], page 6, paragraph [0021])

  The present invention has been made in view of the above circumstances, and the purpose thereof is to form the terminal portion more attractively, the impedance can be easily adjusted, and the flexible flat cable can be thinned. The object of the present invention is to provide a flexible flat cable capable of preventing contact between the shield layer on the outer surface of the flexible flat cable and the linear conductor.

  The flexible flat cable using the annular conductor of the present invention is a flexible flat cable using an annular conductor, comprising an annular conductor, and an upper base film and a lower base film covering the upper and lower sides of the annular conductor, In this flexible flat cable, the flat conductor formed by rolling a part of the annular conductor before covering the upper base film and the lower base film is exposed at the terminal portion of the flexible flat cable, and the flat conductor exposed at the terminal portion. The conductor is supported by the lower base film in the form of being affixed to the lower base film when the annular conductor and the rectangular conductor are affixed to the lower base film, and the lower base film is a flexible flat cable including a terminal portion. It is characterized by being integrally formed over the entire length.

  Preferably, a strip-shaped insulating film is inserted at an end of the upper base film, and a part of the strip-shaped insulating film is not covered with the upper base film.

  Preferably, an insulating coating layer is formed on each outer surface of the annular conductor.

  According to the flexible flat cable of the present invention, the terminal portion can be formed with better appearance, and an inexpensive annular conductor can be used as compared with the conventional flexible flat cable in which the linear conductors are all made of flat conductors. In addition to being able to adjust the impedance and reducing the thickness of the flexible flat cable, it is also possible to avoid contact between the shield layer on the surface of the flexible flat cable and the linear conductor, thereby preventing a short circuit. It becomes possible to prevent.

It is a perspective view of the conventional flexible flat cable. It is sectional drawing of the conventional flexible flat cable. 1 is a perspective view of a flexible flat cable according to an embodiment of the present invention. It is sectional drawing of the flexible flat cable by one embodiment of this invention. It is sectional drawing of the flexible flat cable by other embodiment of this invention. It is the schematic which shows the manufacturing method of the flexible flat cable of this invention. It is the schematic which shows the manufacturing method of the flexible flat cable of this invention. It is the schematic which shows the manufacturing method of the flexible flat cable of this invention. It is a figure which shows the final processing stage of the flexible flat cable of this invention.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a conventional flexible flat cable that uses a flat conductor as a linear conductor. The flat conductor 10 is fixed between the upper film layer 100 and the lower film layer 200 by an adhesive or heat fusion between films. Further, the terminal film 2 formed at the end of the flexible flat cable has no upper film layer, the flat conductor 10 is exposed to the outside, and the terminal section is below the lower film layer 200 at the end of the flexible flat cable. The reinforcement part 300 which supports is attached.

  FIG. 2 shows a cross section of the flexible flat cable (AA cross section in FIG. 1). The flat conductor 10 is disposed between the upper base film 110 and the lower base film 210, and the upper base film 110 and the lower The base film 210 is bonded by the adhesive portion 410.

  An impedance adjustment film 120 made of a dielectric material is attached to the upper surface of the upper base film 110 in order to adjust the impedance. An aluminum foil portion 130 responsible for the ground and shield functions is attached to the upper surface of the impedance adjustment film 120, and a cover film 140 is attached to the upper surface of the aluminum foil portion 130. The upper base film 110, the impedance adjustment film 120, the aluminum foil portion 130, and the cover film 140 are bonded by heat fusion or an adhesive. FIG. 2 shows the upper base film 110, the lower base film 210, and the like. The rest of the bond, except for the bond 410 between, is not shown. The upper base film 110, the impedance adjusting film 120, the aluminum foil part 130, and the cover film 140 form the upper film layer 100.

  Although FIG. 2 shows the case where the lower film layer is composed only of the lower base film 210, the lower film layer may be formed by attaching an impedance adjustment film, an aluminum foil portion, and a cover film to the lower surface of the lower film layer. Good.

  In FIG. 2, when the differential impedance is matched to 100Ω, the thickness of each layer is 50 μm for the cover film 140, 7 μm for the aluminum foil 130, and 150 to 180 μm for the impedance adjustment film 120. The film 110 is 12 μm, the adhesive portion 410 is 68 μm, and the lower base film 210 is 12 μm, and has a total thickness of 299 to 329 μm. The flat conductor has a thickness of 35 μm and a width of about 0.3 mm.

  FIG. 3 is a perspective view of a flexible flat cable according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line BB in FIG.

  The difference from the conventional flexible flat cable shown in FIG. 2 is that the remaining linear conductor excluding the terminal portion is an annular conductor, and a strip-like insulating film is inserted at the end of the upper base film. And that. A part of the strip-shaped insulating film is exposed to the terminal portion side without being covered with the upper base film.

  In FIG. 4, when the differential impedance is matched to 100Ω, the thickness of each layer is 50 μm for the cover film 140, 7 μm for the aluminum foil part 130, and 32 to 50 μm for the impedance adjustment film 120. Since the film 110 is 23 μm, the adhesive portion 410 is 80 μm, the lower base film 210 is 23 μm, and the diameter of the annular conductor 20 is 120 μm, the whole has a thickness of 258 to 276 μm.

  For this reason, compared with the conventional flexible flat cable which uses a flat conductor, it becomes possible to achieve thickness reduction of a linear conductor.

  FIG. 5 is a cross-sectional view of a flexible flat cable according to another embodiment of the present invention, in which an insulating coating layer 22 is formed on the outer surface of the annular conductor 20 to a thickness of about 10 μm, so that the dielectric material is insulated. By providing the coating layer, the thickness of the impedance adjustment film becomes as thin as about 12 to 20 μm, and the thickness as a whole becomes 235 to 243 μm, so that the flexible flat cable can be further thinned.

  The strip-shaped insulating film 500 that is inserted between the upper base film and the flat conductor and is partially exposed without being covered by the upper base film is exposed on the uppermost surface of the upper film layer 100. Is formed from an aluminum foil portion, it is possible to prevent a short circuit from occurring due to contact between the aluminum foil portion and the flat conductor 10 when the terminal portion is folded during use of the flexible flat cable.

  Subsequently, the manufacturing method of the flexible flat cable using the annular conductor of this invention is demonstrated.

  6 to 8 are schematic views for the method of manufacturing the flexible flat cable of the present invention.

  The annular conductor 20 is fed out from the bobbin 610 around which the annular conductor 20 is wound (step 1). A part of the annular conductor 20 that is fed out is processed as a flat conductor used for the terminal portion. At this time, the processing is periodically performed using a roller (620 in FIG. 6) or a press (630 in FIG. 7). This is done by pressing the conductor (step 2).

  The lower base film 210 is fed out from a bobbin 640 around which the lower base film 210 is wound. While the lower base film 210 is being unwound, the reinforcing portion 300 is attached to the lower surface of the lower base film 210 by the heat sealer 650. The reinforcing part 300 is attached to a place where the end of the flexible flat cable is formed (step 3).

  The upper base film 110 is fed out from a bobbin 660 around which the upper base film 110 is wound. The terminal base 111 is perforated by the perforator 670 in the drawn out upper base film 110 (see the enlarged view I in FIG. 6). The terminal exposed portion 111 where the upper base film 110 is cut is for exposing the flat conductor 10 at the terminal portion by cutting the upper base film 110 (step 4). A strip-shaped insulating film 500 is attached to the lower surface of the end of the upper base film by a heat sealer 650 '(see enlarged view II in FIG. 6). Needless to say, when the flexible flat cable according to the embodiment of the present invention without the insulating film 500 is manufactured, the step of attaching the insulating film may be omitted.

  The annular conductor that has undergone step 2 is inserted between the lower base film 210 and the upper base film 110 that have undergone the above-described steps. At this time, the rectangular conductor is positioned at the terminal exposed portion 111 processed in step 4. (Step 5). At this time, the affixing is performed by an adhesive or heat fusion. When an adhesive is used, a step of applying the adhesive immediately before the affixing is performed. 6 to 8 show that heat fusion is performed by the heat fusion roller 680.

  As shown in FIG. 5, when the insulating coating layer 22 is formed on the outer surface of the annular conductor 20, a portion processed as a flat conductor or processed as a flat conductor after step 1 and before step 5. The step of notching the insulating coating layer 22 is further performed. At this time, the notch of the insulating coating layer 22 may be performed using the blade 690 of FIG. 8 or may be performed using a laser device, and various means are adopted for the notch of the insulating coating layer 22. obtain.

  Although FIGS. 6 to 8 do not show the feeding of the impedance adjusting film, the aluminum foil portion, and the cover film, those skilled in the art who understand the explanation of the steps 3 and 4 for feeding the upper and lower base films can perform impedance. It will be understood how to add further films (not shown) such as conditioning films, aluminum foil sections and cover films.

  When the flexible flat cable obtained by the manufacturing method shown in FIGS. 6 to 8 is cut along the one-dot chain line in FIG. 9, the flexible flat cable shown in FIG. 3 is obtained.

DESCRIPTION OF SYMBOLS 100 Upper film layer 200 Lower film layer 300 Reinforcement part 20 Annular conductor 110 Upper base film 210 Lower base film 500 Insulating film 10 Flat conductor

Claims (3)

In a flexible flat cable using an annular conductor, comprising an annular conductor, and an upper base film and a lower base film covering the upper and lower sides of the annular conductor,
A flat rectangular conductor formed by rolling a part of the annular conductor before covering the upper base film and the lower base film is exposed to the terminal portion of the flexible flat cable,
The rectangular conductor exposed at the terminal portion is supported by the lower base film in a form adhered to the lower base film when the annular conductor and the rectangular conductor are adhered to the lower base film.
The flexible flat cable using an annular conductor, wherein the lower base film is integrally formed over the entire length of the flexible flat cable including the terminal portion.   2. The annular conductor according to claim 1, wherein a band-shaped insulating film is inserted at an end of the upper base film, and a part of the band-shaped insulating film is not covered with the upper base film. Flexible flat cable using   The flexible flat cable using the annular conductor according to claim 1, wherein an insulating coating layer is formed on each outer surface of the annular conductor.

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